Jake Peavy has posted a 4.72 ERA and 1.43 WHIP with the Boston Red Sox this season. / David Richard, USA TODAY Sports

by Gabe Lacques, USA TODAY Sports

by Gabe Lacques, USA TODAY Sports

The San Francisco Giants plucked a low-priced piece off baseball's pitching market Saturday when they acquired veteran right-hander Jake Peavy and cash considerations in exchange for two prospects.

Peavy, 33, spent almost exactly a year with the Boston Red Sox, winning four games for them down the stretch after he was acquired from the Chicago White Sox last July 30. He also made three playoff starts as the Red Sox won their third World Series title in 10 seasons.

This season, he went 1-9 with a 4.72 ERA, and his trade marks the start of what could be a vigorous sell-off by the last-place Red Sox.

And he will make an immediate impact with the Giants, where he'll likely supplant journeyman Yusmeiro Petit in the rotation. Petit was scheduled to start tomorrow's series finale at home against the second-place Los Angeles Dodgers.

Peavy figures to enjoy the change of scenery in San Francisco, where he'll work in a pitcher-friendly ballpark. Peavy won the 2007 Cy Young Award as a member of the San Diego Padres.

The Red Sox will receive hard-throwing Class AAA reliever Heath Hembree, as well as 22-year-old starting pitching prospect Rafael Escobar, also at Class AAA. Escobar entered the season as the game's 56th-ranked prospect, according to Baseball America.

Peavy joins Jason Hammel and Brandon McCarthy as pending free agents that teams have targeted in trades for pitching depth, rather than expending significant money and prospects on more accomplished pitchers such as Tampa Bay's David Price and Boston's Jon Lester. He'll join a Giants rotation that's been hindered by both injury and under-performance as they attempt to keep pace with the Dodgers in the NL West.

Ace Matt Cain was placed on the disabled list Tuesday with elbow inflammation, and there's no timetable for his return. Despite his no-hitter, Tim Lincecum (9-6, 3.96 ERA) has had an up-and-down season, as has fellow right-hander Ryan Vogelsong (5-7, 3.99 ERA).